From f212a8ef763384497f790ada0ca60197c7847939 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Sat, 11 Dec 2021 23:31:41 +0100
Subject: [PATCH] Part: set explicit format version number for BRep files to
 support all OCC versions

---
 src/Mod/Part/App/PropertyTopoShape.cpp | 33 ++++++++++----------------
 src/Mod/Part/App/TopoShape.cpp         | 17 ++++++++++++-
 2 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/src/Mod/Part/App/PropertyTopoShape.cpp b/src/Mod/Part/App/PropertyTopoShape.cpp
index 6743402e0a..bf0e888dab 100644
--- a/src/Mod/Part/App/PropertyTopoShape.cpp
+++ b/src/Mod/Part/App/PropertyTopoShape.cpp
@@ -231,16 +231,9 @@ void PropertyPartShape::Restore(Base::XMLReader &reader)
     }
 }
 
-// The following two functions are copied from OCCT BRepTools.cxx and modified
+// The following function is copied from OCCT BRepTools.cxx and modified
 // to disable saving of triangulation
 //
-static void BRepTools_Write(const TopoDS_Shape& Sh, Standard_OStream& S) {
-  BRepTools_ShapeSet SS(Standard_False);
-  // SS.SetProgress(PR);
-  SS.Add(Sh);
-  SS.Write(S);
-  SS.Write(Sh,S);
-}
 
 static Standard_Boolean  BRepTools_Write(const TopoDS_Shape& Sh, const Standard_CString File)
 {
@@ -256,7 +249,15 @@ static Standard_Boolean  BRepTools_Write(const TopoDS_Shape& Sh, const Standard_
   if(!isGood)
     return isGood;
 
+  // See TopTools_FormatVersion of OCCT 7.6
+  enum {
+      VERSION_1 = 1,
+      VERSION_2 = 2,
+      VERSION_3 = 3
+  };
+
   BRepTools_ShapeSet SS(Standard_False);
+  SS.SetFormatNb(VERSION_1);
   // SS.SetProgress(PR);
   SS.Add(Sh);
 
@@ -318,19 +319,7 @@ void PropertyPartShape::SaveDocFile (Base::Writer &writer) const
 
             Base::ifstream file(fi, std::ios::in | std::ios::binary);
             if (file) {
-                //unsigned long ulSize = 0;
                 std::streambuf* buf = file.rdbuf();
-                //if (buf) {
-                //    unsigned long ulCurr;
-                //    ulCurr = buf->pubseekoff(0, std::ios::cur, std::ios::in);
-                //    ulSize = buf->pubseekoff(0, std::ios::end, std::ios::in);
-                //    buf->pubseekoff(ulCurr, std::ios::beg, std::ios::in);
-                //}
-
-                // read in the ASCII file and write back to the stream
-                //std::strstreambuf sbuf(ulSize);
-                //file >> &sbuf;
-                //writer.Stream() << &sbuf;
                 writer.Stream() << buf;
             }
 
@@ -339,7 +328,9 @@ void PropertyPartShape::SaveDocFile (Base::Writer &writer) const
             fi.deleteFile();
         }
         else {
-            BRepTools_Write(myShape, writer.Stream());
+            TopoShape shape;
+            shape.setShape(myShape);
+            shape.exportBrep(writer.Stream());
         }
     }
 }
diff --git a/src/Mod/Part/App/TopoShape.cpp b/src/Mod/Part/App/TopoShape.cpp
index 9ae039e2d1..f3c11745b7 100644
--- a/src/Mod/Part/App/TopoShape.cpp
+++ b/src/Mod/Part/App/TopoShape.cpp
@@ -1024,13 +1024,28 @@ void TopoShape::exportStep(const char *filename) const
 
 void TopoShape::exportBrep(const char *filename) const
 {
+#if OCC_VERSION_HEX >= 0x070600
+    if (!BRepTools::Write(this->_Shape,encodeFilename(filename).c_str(), Standard_False, Standard_False, TopTools_FormatVersion_VERSION_1))
+        throw Base::FileException("Writing of BREP failed");
+#else
     if (!BRepTools::Write(this->_Shape,encodeFilename(filename).c_str()))
         throw Base::FileException("Writing of BREP failed");
+#endif
 }
 
 void TopoShape::exportBrep(std::ostream& out) const
 {
-    BRepTools::Write(this->_Shape, out);
+    // See TopTools_FormatVersion of OCCT 7.6
+    enum {
+        VERSION_1 = 1,
+        VERSION_2 = 2,
+        VERSION_3 = 3
+    };
+    BRepTools_ShapeSet SS(Standard_False);
+    SS.SetFormatNb(VERSION_1);
+    SS.Add(this->_Shape);
+    SS.Write(out);
+    SS.Write(this->_Shape, out);
 }
 
 void TopoShape::exportBinary(std::ostream& out)